This invention relates in general to a steering linkage for directing the coordinated movement of a motor vehicle's steerable wheels from driver inputs to the steering system. In particular, this invention relates to a tie rod steering linkage capable of clearing an interfering underbody obstruction.
Most motor vehicles use a pair of pivoting front wheels in order to direct the intended path of motion. These steering systems typically utilize connecting linkages with pivoting end points called tie rods. These devices are located underneath the vehicle and connect the front steering wheels in order to coordinate their movement in a substantially parallel manner. In operation, a driver turns a steering wheel inside the vehicle to effect desired directional changes. The steering inputs are transmitted from the steering wheel through a steering column and steering gear to a pitman arm which is pivotably connected to a drag link. The drag link is further pivotably connected to the right side spindle structure of a front wheel assembly in a left hand drive vehicle. A tie rod is the connecting link between the front steer wheels.
During operation, the steering inputs of the driver cause the tie rod assembly to move in a lateral and radial direction in order to actuate the steer wheels thus effecting a turn. The lateral and radial movement of the tie rod sweeps an area under the vehicle which must be unrestrained and unobstructed. For a given size of vehicle, the number of components required to be packaged underneath it creates issues because of limited available space. Rather than increase the available space under a vehicle, which increases both weight and cost, components have been modified to create clearances for steering linkage movement. Modifications to engine oil pans, structural cross members and the like have provided the needed clearances but create other problems and expense. For instance, an engine oil pan may be provided with a clearance in the center for steering linkage movement, but requires two drain plugs in order to adequately service the engine. This solution however adds expense and creates customer dissatisfaction. Furthermore, there is a limit to the number and extent that underbody components can be modified to provide sufficient clearance. It is thus desirable to create a steering linkage which can accommodate underbody obstructions without modification to these components and allow for unrestricted lateral and radial movement.